The present invention relates generally to infrared spectropolarimeters, and more particularly to a spectropolarimeter system including Fourier transform infrared spectroscopy and polarimetry.
A polarimeter is an optical instrument for measuring the polarization state of a light beam and polarizing and retarding properties of materials. A spectropolarimeter is an instrument which incorporates a monochromator as a radiation source and makes repetitive spectroscopic measurements as polarization state is changed incrementally. An infrared spectropolarimeter is used to make spectroscopic measurements of the polarization properties of materials in the infrared. However, neither polarimeters nor currently available spectropolarimeters can make spectroscopic measurements of polarization properties easily, with high resolution and with good energy efficiency.
The invention comprises an infrared spectropolarimeter for making spectroscopic measurements of polarization properties and other electro-optic properties of materials over large wavelength intervals in the infrared, and combines Fourier transform infrared spectroscopy and polarimetry. The sample region of the invention includes an achromatic polarizer and retarder on either side of a sample and individually mounted in computer controlled rotating stages for orientation control. Data is taken as a function of wavelength and polarizing element orientation. The result is a 4.times.4 Mueller matrix describing the polarizing, retarding, and scattering properties of the sample as functions of wavelength and, if so configured, electric and magnetic field strength.
It is therefore a principal object of the invention to provide a novel infrared spectropolarimeter system.
It is a further object to provide a spectropolarimeter system combining Fourier transform infrared spectroscopy and polarimetry.
These and other objects of the invention will become apparent as the detailed description of representative embodiments proceeds.